Dual voltage flatiron



June 25, 1963 A. c. DOWNING 3,095,493

DUAL VOLTAGE FLATIRON Filed Jan. 16, 1962 2, Sheets-Sheet 1 June 25, 1963- A. c. DOWNING 3,095,493

DUAL VOLTAGE FLATIRON Filed Jan. 16, 1962 2 Sheets-Sheet 2 'I 6' b 6'l 70 m 76 3 50 64 62 6 76 4a 46 3,095,493 DUAL VOLTAGE FLATHiON Arthur C. Downing, Ontario, Calif assignor to General Electric Company, a corporation of New York Filed Jan. 16, 1962, Ser. No. 166,571 9 Claims. (Cl. 219-25) This invention relates to electric tiatirons which may be selectively operated on two different voltages, and more particularly to such an iron which is protected against inadvertent connection to a high voltage source when the voltage selector is in a low voltage position. The invention may be employed in any dual voltage flatiron, but is particularly useful in connection with travel irons.

During recent years, compact travel irons, such as those having collapsible handles, have become extremely popular due to the ever-increasing number of travelers. In view of the fact that such irons may be carried to many areas of the world where electrical outlets are not available providing current at the conventional U.S. voltages of approximately 110 to 120 volts, and instead have outlets providing power at higher voltage such as 230 volts, it is desirable to provide a travel iron with an arrangement whereby the iron may be easily adapted to either voltage. However, if a fiatiron is connected to a high'voltage source when it is set for low voltage operation, the iron may be quickly damaged to a considerable degree since double voltage applied to the iron heating element will multiply the wattage output by a factor of four. Consequently, it is desirable that some provision be made whereby this potential damage may be minimized. j

Accordingly, it is a primary object of the invention to provide an improved dual voltage .fiatiron protected against accidental connection to a high voltage source.

It is another object of the invention to provide a dual voltage flatiron with an automatic safety feature which minimizes the possibility of the iron being inadvertently or unthinkingly set for low voltage operation when connected to a high voltage power source.

-Another object of the invention is to provide a dual voltage travel iron which is automatically set for high voltage operation whenever the iron is placed in a stowage or non-ironing position and which must be consciously set for low voltage operation when desired.

It is another object of the invention to provide a dual voltage flatiron with a simple heating arrangement which may be easily set for use with the proper voltage source.

Briefly stated, one aspect of the invention relates to a dual voltage flatiron having dual heating elements which are serially connected. A switch may be provided which when closed is connected to shunt or by-pass one of the heater elements. Thus, when the switch is closed, a heat ing current will only flow through one of the heater elements so that the iron may be properly connected to a low voltage source. With the switch open, the iron may be safely connected to a high voltage source in that the heating current will flow through both heating elements. With a dual voltage flatiron, it is, of course, generally desirable to have the wattage consumption approximately the same for both high and low voltage operation in order to obtain the same heating characteristics for the iron at both voltages. the proper relationship between the resistances of the two heating elements and the two voltages may be mathematically computed if a constant wattage at both voltages is desired.

Another aspect of the invention relates to a dual voltage flatiron including a plurality of heater elements and a switch having a low voltage position wherein the elements are connected to be operated at the lower of two voltages and having a high voltage position wherein the elements are connected to be operated at the higher of the two With the heating circuit heretofore described,

, 3,095,423 Patented June 25, 1963 voltages. The iron is provided with a movable handle adapted to move the switch from the low to the high voltage position. Such an arrangement 1s particularly suitable with a travel iron of the type having a handle which is normally moved to a stowage position when the iron is carried to a new location with the traveler since the switch may be automatically moved to the high voltage position when the handle is moved to the stowage position. Thus, the iron may be operated at the higher voltage when next used. If low voltage operation is deslred, the operator must consciously operate the voltage selector switch.

Further features, objects and advantages will become apparent with reference to the following drawings, III). which:

FIG. 1 is a top plan view of a travel iron embodying the invention;

FIG. 2 is a side elevation, partly in section, of the 11011 of FIG. 1;

FIG. 3 is a side elevation of the rear portion of the iron with the handle in the collapsed stowage position and with the handle shown in phantom lines in the iromng position;

FIG. 4 is a sectional view of the rear of the iron;

FIG. 5 is a schematic diagram of the iron electrical circuit; and

HG. 6 is a longitudinal sectional View of a modified form of heating unit which may be used in the fiatiron of the invention.

Referring to FIGS. 14, there is shown an electric travel iron having a soleplate 10 and a cover 12 forming a body, a handle 14, and a power cord 16. It a provision for steam generation is desired, the iron may be provided with a water bottle 18 removably attached to the cover 12. The iron may also be provided with a suitable thermostat and a control lever 20 to vary the ironing temperature together with a dial plate 22 having suitable indicia thereon for indicating the operating temperature at which the control lever 20 is set. Since the detail structure of the iron that has been so far described, including the steaming provision, the thermostat, and the means for integrating these elements, does not form a part of the present invention, a complete description of each will not be given herein. The additional details may be obtained by reference to US. Patent 2,791,045-Finlayson assigned to the same assignee as the instant application.

To facilitate packing in the luggage of the user, the iron handle 14 is pivotally attached to the cover 12 and provided with a latch mechanism by which the handle may be folded from the ironing position as shown in FIG. 2 to the travel position wherein the front end of the handle rests against the cover 12, as shown by FIG. 3. More specifically, a handle bracket 23 is secured to the cover 12 at the rear of the fiatiron and is provided with side walls 24 and 26 to which handle 14 is pivotally secured by suitable fasteners 15.

The rear portion of handle 14 is shaped to provide a pocket 32 adapted to fit over the bracket 23. A latch member 34, preferably formed of a suitable molded heat insulating material, is mounted for pivotal movement within the opening 36 in the bracket by means of a'lower lip 36 positioned between the bracket front wall 28 and the rear' of dial plate 22. A resilient spring member 40 secured to the bracket front wall 28 urges the latch 34 forwardly. The forward movement of the latch 34 is limited by engagement of its upwardly projectingeans 38 with the back surface of bracket front wall 28, as shown by FIG. 2. Thus, it may be seen that with the handle 14 locked in the upright ironing position, as shown in FIG. 2, the shoulder 42 of the handle is supported by the latch 34. To lower the handle to the collapsed travel or stowage position, the latch 34 may be pressed in a clockwise direction against the resiliency of spring 40 until the shoulder 42 on the handle 14 is disengaged from the latch so that the handle is free to pivotldownwardly by virtue of its own weight, until the front of the handle rests against the cover 12, as partially shown by FIG. 3. When the iron is to be used again, the handle 14 need merely be lifted to the ironing position and the spring 46 will automatically snap the top of the latch 34 forwardly so that the latch once more engages shoulder 42 of the handle 14 to lock the handle in its normal operating position. Further constructional details of the pivoted handle and latch mechanism may be obtained by reference to U.S. Patent 2,727,-

322 to Alfred G. Swenson assigned to the same assignee as the present invention.

In accordance with this invention, the fiatiron is provided with dual heating units 46 and 48 which are preferably embedded the soleplate 10. In the embodiment of FIGS. 1-4, two separate sheathed tubular heating units 46 and 48 are'spaced in parallel relationship and form U-shapes terminating at terminals 50 and 52 for unit 46, and 54 and 56' for unit 43, as best seen in FIG. 4. Each of the units is provided with a suitable coiled resistance element which is centrally supported and insulated with respect to its surrounding tube by a mass of electrically insulating heat conducting material, such as compacted magnesium oxide.

In accordance with this invention, when the iron is to be operated on the higher of two voltages, the two sections of the dual heating element are electrically connected in series; while for low voltage operation only one of the sections of the heating element is used. For both low voltage and high voltage operation, the usual adjustable flatiron thermostat (shown schematically at 74 in FIG. is connected in the circuit. In accomplishment of the above and with reference to FIGS. 2 and 4, one of the power lines :from the electrical supply cord is connected to a terminal 68 supported on an insulating block 62. This terminal 68 preferably is connected to one terminal of the adjustable thermostatic switch, with the opposite terminal of the thermostatic switch being connected to terminal screw 60 employed to support a jumper 58 and connect it to terminal 50 of the outside heating element 46. The opposite terminal 52 of the outside heating element is connected through a jumper 66 to terminal 56 of the inside heating element, while the opposite terminal 54 of the inside heating element is connected to the other side of the line by terminal bracket 67. Thus, it may be seen that with the circuit as described above, both heating elements are electrically connected in series.

For low voltage operation, one of the heating elements .is removed from the circuit, and in the embodiment illustrated by FIGS. 1 through 4, the outside tubular heating element 46 is by-passed for this purpose. To accomplish this, a voltage selector switch is connected from the terminal 52 ot the outside heating element to its opposite terminal 50, so that when the switch is closed, no electric current passes through the resistance element of the outside heater. "Dhis voltage selector switch, as best shown in FIG. 2, involves a spring arm 73 carrying contact 72 on one end thereof for cooperation with a fixed contact ,70 carried by the insulator 62 and terminating with the terminal screw 60 previously referred to in connection with FIG. 4.

A clearer understanding of the heating circuit may be obtained with reference to FIG. 5 which shows a schematic version of the circuit wherein the elements in FIG. 5 corresponding to those in FIG. 4 have been given like numerals. In addition, the circuit in FIG. 5 is provided w1th a suitable thermostatic bimetallic switch 74 for controlling the temperature. As can be seen in FIG. 5, the resistances 48 and 46 representing the heating units are serially connected to the line terminals. To enable the flatiron to be operated on two different voltages, the voltage selector switch 7 0, 72 is connected to shunt the heatng unit 46 when the switch is closed.

In order to obtain the desired operating characteristics, it is preferable that a dual voltage fiatiron have approximately the same wattage rating at both high and low voltage. Assuming equal wattage ratings, in a dual voltage llatiron having its heating elements connected as shown in FIG. 5, the relationship between the two heating element resistances may be expressed as follows:

Where R is the resistance of heating unit 46; R is the resistance of heating unit 48; V is the higher voltage to be applied; and V is the lower voltage. When V is roughly twice the value of V such as 230 to or volts, R equals 3R If a different relationship exists between the two voltages to be employed, the relationship between the proper resistances of the two heating units will, of course, be varied accordingly.

In accordance with the invention, the voltage selector switch 70, 72 may be controlled by suitable means such as a bellcrank lever 76 pivotally supported on suitable pins or shafts 85 extending from the walls 24 and 26 of bracket 23. The lower end 73 of the lever is preferably made of insulating material and engages flexible arm 73, which when not restrained by the insulated end 78 holds contact 72 out of engagement with fixed contact 70. The opposite end of the lever 76 is formed with a projection 80 extending through a slot 83, FIG. 3, in bracket side wall 26 and has mounted thereon a manual control button 82 for operating the lever. Suitable markings may be pro vided on the button to indicate the proper switch position for the respective voltages, as shown in FIG. 1. When the control button 82 is in its lower position as shown in FIG. 2, the insulated end 78 is not restraining flexible arm 7 3 and thus the movatile contact 72 is not in engagement with fixed contact 7 6 so that the iron may be sately operated on a high voltage source. In this position, an insulating projection 84 depending from the cover 12 limits the movement of arm 73 and electrically insulates the arm from the cover.

If the fiatiron is to be operated by a low voltage source, the operator need simply move the control button upwardly so that the lever 76 is pivoted in a clockwise direction, causing its insulated end 78 to force the flexible arm 78 downwardly closing the contacts 7 0, 72, thereby shunting heater coil 46. When the lever 76 is in the low voltage position, its insulated end 78 is positioned to the left of the lever pivotal axis 85, as seen in FIG. 3, so that the resiliency of arm 73 urges the lever in a clockwise direction, and since the clockwise movement is limited by the slot 83 or the handle 14, the lever 76 is locked in the low voltage position until the lever is moved to the high voltage position by a superior counterclockwise force applied to the'button end of the lever.

Such an arrangement as heretofore described would be entirely satisfactory so long as the operator would always remember to set the selector switch tor the proper voltage prior to connecting the iron to a power supply.

However, if the switch is set ior low voltage operation and then connected to a high voltage power outlet, the

iron could be seriously damaged in a relatively short time. The present invention minimizes the possibility of such danger by providing an arrangement whereby the switch 70, 72 is automatically placed in the high voltage position whenever the flatiron handle 14 is folded into the stowage position. Since the iron is less bulky with the handle folded and since the handle must he collapsed to enable the iron to be completely received within its storage box, the user would normally fold the handle when the travel iron is to be taken, usually in the users luggage, to a new location. In accordance with the invention, this safety feature may be obtained by positioning the control lever 7 6 so that the manual control button 82 is positioned immediately beneath the handle 14 when the handle is in the ironing positionyand the button is in the low voltage setting. By this arrangement, when the handle is pivoted to the folded stowage position, it engages the manual control button 82 causing the lever 76 to pivot in a counterclockwise direction so that insulated end 78 is moved away from flexible arm 73, allowing switch contact 7-2 to disengage contact 70 due to the resiliency of flexible arm 73. In other words, as the handle 14 is collapsed, the heating circuit is automatically placed in the high voltage position. When the iron is to he used again in a new location and is connected to a high voltage outlet, the flatiron will not be damaged even though the iron selector switch had been previously set for low voltage operation. The operator need not remember to set the selector switch for high voltage operation when the handle is first placed in the ironing position. If, however, in the new location the llatiron is to be operated on a low voltage source, the operator need simply, but consciously, move the control button 82 upwardly to the low voltage position as previous described. Thus, it will be appreciated that with this uniquely arranged handle-operated switch the dual voltage iron is relatively foolproof.

In another embodiment of the invention, the two individual heating units 46' and 48 may be combined into a single heating unit having two different resistance heating elements shown in FIG. 6. The single heating unit comprises an outer tube 86 containing an outer helix heating coil 88 concentric with an inner helix coil 90. The inner coil '90 is connected to a rod-like terminal =92 which is positioned within and insulated from a tubular terminal 94 attached to outer coil 88, and the coils are connected to a common terminal 96 at their opposite ends. The coils and the terminals may be insulated from the tube 86 by suitable electrically insulating, heat conducting material such as magnesium oxide 98. In using the heating unit with the previously described flatiron, hoth coils 88 and 90 would be connected to operate in series for high voltage operation and one would be bypassed for low voltage operation.

The particular embodiment described herein is, of course, merely an example of the invention, and it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the invention in its broader aspects. More specifically, the particular lever and switch arrangement heretofore described is merely an example of one of many which could be operated by a movable tlatiron handle. Therefore, it is intended in the appended claims to cover all such changes and modifications which fall within the true spirit and scope of the invention.

Having thus described the invention, what is claimed is:

l. A dual voltage travel iron including,

(a) a plurality of heater elements,

(b) a switch having a low voltage position wherein said heater elements are connected to be operated at the lower of the two voltages and having a high voltage position wherein said heater elements are connected to be opera-ted at the higher of said two voltages.

(c) a movable handle for manipulating the iron adapted to be moved from a raised operative position to a collapsed stowage position,

(d) means actuated by said handle to automatically place said switch in the high voltage position when the handle is placed in the stowage position, and

(e) manually operable means to return said switch to the low voltage position.

2. A dual voltage travel iron including,

(a) a plurality of heater elements,

(la) a switch having a low voltage position wherein said heater elements are connected to be operated at the lower of the two voltages and having a high voltage position wherein said heater elements are connected to be operated at the higher of said two voltages,

(c) a movable handle for manipulating the iron adapted to be moved from an operative position to a stowage position,

(d) means actuatedby said handle to automatically place said switch in the high voltage position when the handle is placed in the stowage position, and

( e) means to manually operate said switch when the handle is in the ironing position.

3. A dual voltage iron comprising,

(a) first and second serially connected heater elements,

(b) a switch connected to shunt said second heater element when closed,

(0) a handle for manipulating the iron adapted to be moved from an operative position to a compact folded stowage position,

(d) means actuated by said handle to automatically open said switch when the handle is moved to the stowage posit-ion, and

(e) manual means movable independently of said handle to close said switch.

4. A dual voltage travel iron comprising,

-(a) first and second heater elements serially connected toa pair of line terminals,

(b) a switch connected to shunt said second heater ele* ment when closed,

(0) a collapsible handle adapted to be folded from an ironing position to a compact stowage position,

(a!) means actuated bysaid handle to automatically open said switch when the handle is placedin the stowage position, and

(e) means to manually operate said switch when the handle is in the ironing position.

5. In an electric flatiron,

(a) a body including a soleplate and a cover,

(b) a handle pivoted at its rear end to the rear of said body,

(0) manually operated means for releasing said handle to allow the .front end of the handle to be pivoted from an ironing position towards the cover into a compact stowage position,

(d) a plurality of heater elements attached to said soleplate and connected to a pair of line terminals,

(e) a switch having a low voltage position wherein said heater elements are connected to be operated at the lower of two voltages and having a high voltage position wherein the heater elements are connected to be operated at the higher of said two voltages, and

(f) a switch control lever mounted on said body adapted to be actuated by said handle to automatically move said switch from the low to the high voltage position as the handle is placed in the stowage position and manually movable independently to either position.

6. 'In an electric flatiron,

(a) a body including a soleplate and a cover,

(b) a handle pivoted at its rear end to the rear of said body,

('0) manually operated releasable latch means which permits the handle to be pivoted from an ironing position whereinthe latch supports the handle to a stowage position wherein the front of the handle rests on the cover,

(d) first and second heating units embedded in said soleplate and serially connected to a pair of line terminals,

(e) a switch connected to shunt said second heater unit when closed,

(1) a switch control lever pivotally mounted on a bracket supported on the rear of said cover and adapted to be actuated by said handle to automatically open said switch when the handle is placed in the stowage position, and

(g) said lever having an external control button by which the lever may the manually operated when the handle is in the ironing position to open or close said switch.

7. Adual voltage travel iron comprising,

(a) .a first heater element having a resistance R ([2) a second heater element serially connected to the first heater element and having a resistance R approximately equal to where V equals a voltage suitable for use with R to obtain a predetermined wattage and V equals a voltage larger than V to he used with R and R serially-connected to obtain said predetermined watt- (0) a manually operable switch connected to shunt said second heater element when closed,

(d) a handle for manipulating the iron adapted to be moved from a raised ironing position to a collapsed stowage position, and

(e) means operated by movement of said handle to automatically-open said switch when the handle is placed in the stowage position.

8. A dual voltage travel iron comprising,

(a) a first winding having a resistance R (b) a second Winding serially connected to the first winding and having a resistance R approximately equal to where V equals a voltage suitable for use with R to obtain a predetermined wattage and V equals a voltage larger than V to he used with R and R serially connected to obtain said predetermined watt- (c) a'switch connected to shunt said second heater winding when closed,

(d) a handle adapted to be moved from an ironing position to a stowage position, and

(e) means operated by said handle to automatically open said switch when the handle is placed in the stowage position,

(f) said means being adapted to be manually moved to open or close said switch when the handle is in the ironing position.

9. A dual voltage travel iron comprising,

(a) a tubular heating unit containing two resistance heating elements,

([2) a manually operable switch having a low voltage position wherein said heating elements are connected so that the heating unit is adapted to have the lower of two voltages applied thereto and having a high voltage position wherein the heating unit is adapted to have applied thereto the higher of said two voltages,

'(c) a handle for manipulating the iron adapted to be moved from an operative ironing position to a collapsed stowage position, and

(0!) means operated by said handle to automatically move said switch to the high voltage position when the handle is placed in the stowage position.

References Cited in the file of this patent UNITED STATES PATENTS 1,306,542. Hill June 10, 1919 2,215,029 Braun Sept. 17, 1940 2,632,934- Huck et a1. Mar. 24, 1953 2,701,293 Russell 'Feb. 1, 1955 2,7271131 Russell Dec. 13, 1955 2,727,322 Swenson Dec. 20', 1955 2,846,536 Drugmand et a1 Aug. 5, 1958 FOREIGN PATENTS 12330 Great Britain May 26, 19 1 3 of 1912 278,349 Italy Oct. 7, {1930 646,328 Great Britain Nov. 22, 1950 

1. A DUAL VOLTAGE TRAVEL IRON INCLUDING, (A) A PLURALITY OF HEATER ELEMENTS, (B) A SWITCH HAVING A LOW VOLTAGE POSITION WHEREIN SAID HEATER ELEMENTS ARE CONNECTED TO BE OPERATED AT THE LOWER OF THE TWO VOLTAGES AND HAVING A HIGH VOLTAGE POSITION WHEREIN SAID HEATER ELEMENTS ARE CONNECTED TO BE OPERATED AT THE HIGHER OF SAID TWO VOLTAGES. (C) A MOVABLE HANDLE FOR MANIPULATING THE IRON ADAPTED TO BE MOVED FROM A RAISED OPERATIVE POSITION TO A COLLAPSED STOWAGE POSITION, (D) MEANS ACTUATED BY SAID HANDLE TO AUTOMATICALLY PLACE SAID SWITCH IN THE HIGH VOLTAGE POSITION WHEN THE HANDLE IS PLACED IN THE STOWAGE POSITION, AND (E) MANUALLY OPERABLE MEANS TO RETURN SAID SWITCH TO THE LOW VOLTAGE POSITION. 